Screened RFI-signal through-lets (RFI=Radio Frequency Interference) of the aforesaid kind are known to the art. These through-lets, however, are often of complicated construction and the work involved in fitting the actual through-let and in mounting the through-let in the associated equipment is time-consuming. As a result, difficulties arise in achieving a complete screen around the through-let, and also results in problems of keeping the through-let in position in the screen wall.